Topography of duodenum and Pancreas (with scheme)

Duodenum

Duodenum and Pancreas (syntopy) - Dafni's drawing

The duodenum can be divided into four parts which form a C shape and are about 25cm long together:

Superior - Projects to level of L1. The superior part is intraperitoneal, and its wider proximal lumen is called duodenal ampulla.

Descending - Descends along L1-L3. Has the major duodenal papilla that separates the blood supply and lymphatic drainage according to developmental origin from foregut to midgut. Has a minor duodenal papilla above.

Horizontal - Crosses the vertebral column at the level of L3. Passes over the IVF and is crossed anteriorly by the superior mesenteric artery and vein.

Ascending - (L2) Originates at the inferior border of the pancreas to level of L2 to enter the Duodenojejunal junction left to the midline.

The duodenum curves from the anterior aspect of the pancreas to the posterolateral aspect, so that the head of pancreas lies within the duodenal curve.

Pancreas

Level of L1: Body and tail of pancreas

• The body creates the omental bursa behind the stomach (omental tuberosity).
• The tail extends to the hilum of the spleen.
• The splenic artery courses at the superior border of the body and tail.
• The splenic vein is posterior to the body and merges with the superior mesenteric vein posterior to the neck of pancreas forming the hepatic portal vein.

Level of L2: head & uncinated process

• The inferior vena cava lies posterior to the head.
• The bile duct enters the head of pancreas from posterior.